Interface catalytic regulation via electron rearrangement and hydroxyl radicals triggered by oxygen vacancies and heavy metal ions

Xiang-Yu Xiao; Zong-Yin Song; Chong-Chong Zhang; Yong-Huan Zhao; Zhi-Wei Gao; Shi-Hua Chen; Pei-Hua Li; Yu-Feng Sun; Meng Yang; Xing-Jiu Huang

doi:10.1039/d2sc06762e

Interface catalytic regulation via electron rearrangement and hydroxyl radicals triggered by oxygen vacancies and heavy metal ions

Chem Sci. 2023 Feb 17;14(11):2960-2970. doi: 10.1039/d2sc06762e. eCollection 2023 Mar 15.

Authors

Xiang-Yu Xiao^{1

2}, Zong-Yin Song^{1

2}, Chong-Chong Zhang³, Yong-Huan Zhao^{1

2}, Zhi-Wei Gao^{1

2}, Shi-Hua Chen¹, Pei-Hua Li¹, Yu-Feng Sun³, Meng Yang¹, Xing-Jiu Huang^{1

2}

Affiliations

¹ Key Laboratory of Environmental Optics and Technology, Environmental Materials and Pollution Control Laboratory, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences Hefei 230031 P. R. China myang@iim.ac.cn xingjiuhuang@iim.ac.cn.
² Department of Materials Science and Engineering, University of Science and Technology of China Hefei 230026 P. R. China.
³ College of Mechanical and Automotive Engineering, Anhui Polytechnic University Wuhu Anhui 241000 PR China.

Abstract

Although the enhanced intrinsic activities of some nano-metal oxides are obtained by manufacturing oxygen vacancies (OVs), the effect of multiple roles of OVs is ambiguous. Herein, an interface catalytic regulation via electron rearrangement and hydroxyl radicals (˙OH) was proposed with the designed ZrO₂ hollow sphere rich in OVs (V_o-rich ZrO₂). Surprisingly, it was shown that the catalytic ability of V_o-rich ZrO₂ was 9.9 times higher than that of ZrO₂ with little OVs in electrochemical catalytic reduction of Pb(ii). It was found that the generation of Zr²⁺ and Zr³⁺ caused by OVs results in the rearrangement of abundant free electrons to facilitate the catalytic reaction rates. The longer bond length between V_o-rich ZrO₂ and reactants, and the lower adsorption energy are beneficial for reactants to desorb, improving the conversion rates. Besides, the produced ˙OH were captured which were induced by OVs and trace divalent heavy metal ions in in situ electron paramagnetic resonance (EPR) experiments, contributing to lowering the energy barriers. This study not only revealed the enhanced interface catalytic effect of electron rearrangement and generated ˙OH triggered by OVs, but also provided unique insights into interface catalytic regulation on nano-metal oxides simulated by OVs.